1. Field of the Invention
The invention relates to a source driver and a display device. Particularly, the invention relates to a source driver having an over current protection mechanism and a display device using the same.
2. Description of Related Art
FIG. 1 is a structural schematic diagram illustrating a conventional liquid crystal display (LCD). Referring to FIG. 1, the conventional LCD 100 includes a display panel 110, a plurality of source drivers 121-126 and a power controller 130. The power controller 130 is disposed on a printed circuit board (PCB) 140, and supplies power to the source drivers 121-126 through a resistor R1. The source drivers 121-126 are packaged on flexible circuit boards 151-156 through chip on flex (COF) bonding structures, and receive the power from the power controller 130. In this way, the source drivers 121-126 can convert digital image data into corresponding driving voltages to drive pixels in the display panel 110.
Moreover, in the conventional LCD 100, an over current protection circuit 160 is generally disposed in the power controller 130, and a main reason thereof is that during an assembling process of a LCD, poor wire bonding generally causes unnecessary short circuit between the wires. For example, during a packaging process of the source drivers 121-126, originally independent output channels are probably connected due to the poor wire bonding. Now, the shorted output channels may cause the source drivers generating a large current to damage the internal circuit.
To avoid occurrence of the above problem, when the large current is generated, the over current protection circuit 160 can cut off the power supplied by the power controller 130. In this way, all of the source drivers 121-126 stop operations, so as to avoid being damaged by the large current. However, although such over current protection method can protect the system, it also increases difficulty in testing of the display, since when the over current protection mechanism is activated, all of the source drives stop operations, so that it is hard for a testing engineer to determine the malfunctioned source driver or a block that has a connection problem. Now, the testing engineer has to perform testing to each of the source drivers and related connections of each of the blocks. Therefore, not only a time required for testing the display is increased, but also a labour cost is increased.